Leading Edge Slats on the Me-109

[Crumpp]

Heres a really nice and simple way to illustrate this for you...you have pitched up in your 109....inboard section of the wing begins to stall and the lovely slats have deployed keeping you nice and safe....you keep pulling and your angle of attack is still increasing (even for the magic outboard section of the wing).....now you have pitched so much that you have stalled the outboard section of the wing

Let me fix that for you as it the highlighted portion is the source of your confusion on this issue.

Heres a really nice and simple way to illustrate this for you...you have pitched up in your 109....inboard section of the wing IS STALLED and the lovely slats have deployed keeping you nice and safe....

Why don't you schedule some flying lessons and explain to the instructor how the elevator can increase angle of attack AFTER the wing is stalled.

[ACE-OF-ACES]

Originally Posted by Glider

Still Wondering

Crumpp
What do you tell your students about leading edge slots? Do you tell them:-

a) That they are devices that delay the stall or
b) That they are anti spin devices

Just wondering

As are the rest of us..

But I suspect Crump will avoid answering this question because any atemp in doing so will only highlight how silly his position is on the matter.

[taildraggernut]

Originally Posted by Crumpp

Let me fix that for you as it the highlighted portion is the source of your confusion on this issue.

Why don't you schedule some flying lessons and explain to the instructor how the elevator can increase angle of attack AFTER the wing is stalled.

Really? that's the best you've got? instead of answering the question you just keep playing the 'why don't you go take flying lessons because I don't need to because the movie TOP GUN was all about me'?

Heres a nice link to some material us actual flying instructors use..

Standard Stall Recovery (SSR) from a fully stalled condition is then taught. Recovery
action should be initiated at the first full stall sign. Noting the entry height will again
enable the height lost during recovery to be demonstrated illustrating the increased
height loss in the event of a full stall. This emphasises the benefit of early recognition
and recovery at the incipient stage.
Recovery without power can then follow. This clarifies that to recover from the stall the
angle of attack must be reduced using the elevator, which remains effective in the stall.

That bit again..

angle of attack must be reduced using the elevator, which remains effective in the stall.

taken from GAPAN (Guild of Air Pilots and Air Navigators)..

www.gapan.org/file/666/teaching-stalling.pdf

Home website..

https://www.gapan.org/

I should remind you that slats deploy before the main wing has actually stalled which makes my original text quite correct thanks.

While were at it perhaps you could educate us all on exactly what phenomenon takes place that renders elevators inoperative when the wing is stalled? I'm pretty sure if there is airflow over the elevator then it has something to create a pitch force with

Heres my ORIGINAL question without ammendment as it's the one that makes sense and highlighted in BOLD is the part I'd like to know more about.

Heres a really nice and simple way to illustrate this for you...you have pitched up in your 109....inboard section of the wing begins to stall and the lovely slats have deployed keeping you nice and safe....you keep pulling and your angle of attack is still increasing (even for the magic outboard section of the wing).....now you have pitched so much that you have stalled the outboard section of the wing because you have gone beyond the maximum angle of attack the slats allow.......please explain from this point what magic force is in place to prevent a spin.

please, no more cheap insults or suggestions I need to educate myself, that stuff gets old real quick, just answer my question.

Thanks in advance.

[Glider]

Originally Posted by Crumpp

Why don't you schedule some flying lessons and explain to the instructor how the elevator can increase angle of attack AFTER the wing is stalled.

If I ask the flying instructor the following what do you think the reply will be:-

What do leading edge slots do, do they:-

a) Delay the stall or
b) Are they anti spin devices

Just wondering if my flying instructor give the same reply, that you who has told us is a CFI would give.

My money is on (A) what do you think?

[*Buzzsaw*]

Originally Posted by TomcatViP

C'mon a lot of modern fighter use slat and are supersonic. I don't see any link.

Modern slats may be intended to achieve improvements in lift at low speeds in the same way as the 109's slats, but they are not all the same design as the 109's. Gaps are almost imperceptible in comparison to the 109's when not deployed, when deployed, they move forward almost seamlessly, there is nothing in the way of the large open gaps displayed by the 109's slats when deployed. Modern leading edge flaps are a completely different system. These modern leading edge flaps are also computer controlled, with a degree of sophistication in their deployment which makes the 109's slats appear crude at best.

Slats of the 109 era do confer some benefits, but they also impose penalties.

[Crumpp]

Glider says:

If I ask the flying instructor the following what do you think the reply will be:-

What do leading edge slots do, do they:-

a) Delay the stall or
b) Are they anti spin devices

Just wondering if my flying instructor give the same reply, that you who has told us is a CFI would give.

My money is on (A) what do you think?
Today 05:49 PM

To deliver spark to an engines combustion chamber, we use a "spark plug"! Does it plug up the spark? NO, it is just the name of the device used to provide an ignition source.

When we design a spin resistant airplane, we use anti-spin devices to build that spin resistance.

Because folks do not understand the technical terminology, which I been nice enough to explain which is unfortunately lost in the zeal to prove me wrong by a small select portion, the community ends up with all these pointy-tin foil hat theories that have nothing to do with the spin resistant design of the Bf-109.

[Crumpp]

Modern slats may be intended to achieve improvements in lift at low speeds in the same way as the 109's slats, but they are not all the same design as the 109's. Gaps are almost imperceptible in comparison to the 109's when not deployed, when deployed, they move forward almost seamlessly, there is nothing in the way of the large open gaps displayed by the 109's slats when deployed. Modern leading edge flaps are a completely different system. These modern leading edge flaps are also computer controlled, with a degree of sophistication in their deployment which makes the 109's slats appear crude at best.

Slats of the 109 era do confer some benefits, but they also impose penalties.

You must be trolling in this reply.

LE flaps are completely different in the aerodynamics from slots or automatic slats.

LE flaps change the camber of the wing and slots/automatic slats energize the boundary layer.

Do you know what a camber change means and how it looks on the polar? A camber changes shifts the entire polar to the left. This has the effect of producing the same coefficient of lift at a lower angle of attack. TE flaps are also camber changers and this is the primary reason we use them on landing. It allows the nose to be lowered so the pilot can see the runway without sacrificing coefficient of lift. Depending on the design, the flap can also raise the maximum coefficient of lift but this too will shift to the left on the polar.

While they are both high lift devices, you are comparing apples and oranges so your post makes no sense at all.

[taildraggernut]

Originally Posted by Crumpp

To deliver spark to an engines combustion chamber, we use a "spark plug"! Does it plug up the spark? NO, it is just the name of the device used to provide an ignition source.

When we design a spin resistant airplane, we use anti-spin devices to build that spin resistance.

Because folks do not understand the technical terminology, which I been nice enough to explain which is unfortunately lost in the zeal to prove me wrong by a small select portion, the community ends up with all these pointy-tin foil hat theories that have nothing to do with the spin resistant design of the Bf-109.

Let's call them fish blankets instead, that should avoid any confusion we are after all all talking about the same device, but just out of interest are you really saying that anti-spin is somewhat of a mislabeling for their actual function?.....or in essence admitting your own pointy tin foil hat zeal to claim the 109 as unspinnable is flawed?

[*Buzzsaw*]

Originally Posted by Crumpp

You must be trolling in this reply.

LE flaps are completely different in the aerodynamics from slots or automatic slats.

LE flaps change the camber of the wing and slots/automatic slats energize the boundary layer.

Do you know what a camber change means and how it looks on the polar? A camber changes shifts the entire polar to the left. This has the effect of producing the same coefficient of lift at a lower angle of attack. TE flaps are also camber changers and this is the primary reason we use them on landing. It allows the nose to be lowered so the pilot can see the runway without sacrificing coefficient of lift. Depending on the design, the flap can also raise the maximum coefficient of lift but this too will shift to the left on the polar.

While they are both high lift devices, you are comparing apples and oranges so your post makes no sense at all.

Salute Crrump

You clearly haven't read the post which I was responding to.

I do not say the 109 era slats were equivalent to modern era LE flaps, that claim was put forward by Tomcat. In fact I was pointing out the big differences between these devices.

On the issue of 109's entering spins: It's clear your insistence, against all the evidence presented, that the 109's slats made the aircraft "spin proof", is simply not factual. Do they lessen the chance of a spin? Yes, I doubt anyone here would disagree.

However, this does not seem to be enough for you.

We are now in the usual counterproductive and meaningless back and forth which always seems to occur when you enter a thread.

Whether or not other posters agree partially with your arguments seems to make no difference, you seem incapable of accepting the central concept of healthy debate, that being differing viewpoints allow an arrival at a conclusion which may not agree with either side's starting position.

Without any apparent willingness on your part to consider other viewpoints, there is point to further discussion.

[Crumpp]

That bit again..

Taildragger can you explain what reducing the angle of attack to prevent a stall has to do with your claim of raising the nose on the BF-109 with the elevator to completely stall the energized boundary layer of the tips while the rest of the wing is stalled?

I don't see the connection.